The present disclosure relates to power tools driven by an electric motor, and more specifically, the present invention relates to oscillating power tools. Power tools utilize the rotation of an electric motor to provide useful torque for operations such as cutting.
In one construction, the disclosure provides an oscillating power tool including a main body housing a motor. The oscillating power tool further includes a drive mechanism operatively coupled to the motor. The drive mechanism includes a shaft that is selectively driven in a first rotational direction and in a second rotational direction opposite the first rotational direction. The oscillating power tool further includes an output mechanism operatively coupled to the drive mechanism. The drive mechanism converts rotation of the shaft into oscillation of the output mechanism. The drive mechanism is operatively coupled to drive the output mechanism to provide a first degree of oscillation when the shaft is driven in the first rotational direction and operatively coupled to drive the output mechanism to provide a second degree of oscillation when the shaft is driven in the second rotational direction, the second degree of oscillation different from the first degree of oscillation.
In another construction, the oscillating power tool includes a main body housing a motor. The oscillating power tool further includes a drive mechanism having a main shaft rotatable about a first axis and selectively rotatable in a first rotational direction and in a second rotational direction. An output mechanism is operatively coupled to the drive mechanism. The output mechanism is configured to oscillate. The drive mechanism converts rotation of the main shaft into oscillation of the output mechanism. The drive mechanism includes an eccentric member defining a second axis parallel to and offset from the first axis. The eccentric member is movable with respect to the main shaft between a first position having a first offset distance between the second axis and the first axis and a second position having a second offset distance between the second axis and the first axis, wherein the first offset distance is different from the second offset distance. The first offset distance corresponds to a first degree of oscillation of the output mechanism and the second offset distance corresponds to a second degree of oscillation of the output mechanism. The first degree of oscillation is different from the second degree of oscillation.
In yet another construction, the disclosure provides a method of changing the degree of oscillation of an output shaft in a power tool having a motor and a drive mechanism configured to convert rotation of the motor into oscillation of the output shaft. The drive mechanism includes a fork for transferring motion from the drive mechanism to the output shaft and a main shaft configured to rotate about a first axis in a first direction and to rotate in a second direction opposite the first direction. The method includes providing an eccentric member operatively coupled to the main shaft and to the forked member and having a variable eccentricity to effectuate a change in the degree of oscillation of the output shaft of the power tool.
Other aspects of the disclosure will become apparent by consideration of the detailed description and accompanying drawings.
Before any embodiments or constructions of the disclosure are explained in detail, it is to be understood that the disclosure is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The disclosure is capable of other embodiments and constructions and of being practiced or of being carried out in various ways. Also, it should be understood that the phraseology and terminology used herein are for the purpose of description and should not be regarded as limiting.
The head 18 is an oscillating head and the motor 22 in the illustrated construction is 12V-DC, 2.0 Amps no load current. The motor 22 includes a motor drive shaft 46 and is either a reversible/bidirectional motor, as shown in the illustrated construction, or in other constructions may be a single-direction motor engaged with a reversing drive (not shown) for selectively reversing the direction of rotation of the motor drive shaft 46. For example, the reversing drive (not shown) may include a reversing mechanism driven by the motor drive shaft 46 and an intermediate shaft driven by the reversing mechanism in a direction opposite the direction of the motor drive shaft 46. In other constructions, other suitable motors may be employed, such as an alternating current (AC) motor, a pneumatic motor, etc. In yet other constructions, a variable speed or multi-speed motor may be employed.
The handle 14 includes a housing 26 and a grip portion 30 providing a surface suitable for grasping by a user to operate the power tool 10. The housing 26 generally encloses the motor 22, which has a motor drive shaft 46 extending therefrom. A longitudinal axis A (
The power tool 10 includes a removable and rechargeable battery pack 34. In the illustrated construction, the battery pack 34 is a 12-volt battery pack and includes three (3) Lithium-ion battery cells. In other constructions, the battery pack may include fewer or more battery cells such that the battery pack is a 14.4-volt battery pack, an 18-volt battery pack, etc., or the like. Additionally or alternatively, the battery cells may have chemistries other than Lithium-ion such as, for example, Nickel Cadmium, Nickel Metal-Hydride, or the like. In other constructions, other suitable batteries and battery packs may be employed. In yet other constructions, the power tool 10 may include a power cord so that it may be powered by a remote source of power, such as a utility source of AC connected to the cord. In yet other constructions, the power tool 10 may be pneumatically powered or powered by any other suitable source.
The handle 14 also includes an actuator 54 (
The head 18 includes a drive mechanism 58 for converting rotary motion of the motor drive shaft 46 into oscillating motion of an output mechanism 60. As shown in
The forked member 82 is coupled to the clamping shaft 62 by a sleeve 98 and includes two arms 102. The arms 102 are positioned adjacent generally opposite sides of the ball bearing eccentric member 78, and each arm 102 includes a contact portion 106 that engages an outer circumferential surface of the ball bearing eccentric member 78. As the ball bearing eccentric member 78 rotates and wobbles about the axis A, the ball bearing eccentric member 78 pushes each contact portion 106 in an alternating fashion to cause the forked member 82 to oscillate. Thus, the forked member 82 wobbles and oscillates about the axis B to convert the eccentric rotary motion of the ball bearing eccentric member 78 about the axis A into oscillating motion of the hollow spindle 98 about the axis B.
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In the illustrated construction, the first eccentric offset distance 202 is larger than the second eccentric offset distance 214, meaning that the first degree of oscillation is larger than the second degree of oscillation. In the illustrated construction, the larger degree of oscillation occurs when the motor is operating in the reverse direction and the smaller degree of oscillation occurs when the motor is operating in the forward direction. In other constructions, the first eccentric distance 202 may be smaller than the second eccentric distance 214. Accordingly, the larger degree of oscillation may occur when the motor operates in the forward direction and the smaller degree of oscillation may occur when the motor is operating in the reverse direction. In alternate constructions, the size of the first offset distance and the second offset distance may be varied (e.g., by altering the dimensions of the protrusion 138 of the eccentric bore 86 and the cutout 178 of the eccentric member 70) to effectuate other degrees of oscillation as desired.
As discussed above, the ball bearing eccentric member 78 is secured to the shaft tip 94. As the eccentric member 70 is rotated by the main shaft 66, the ball bearing eccentric member 78 wobbles about the axis A. The eccentric member 78 pushes each contact portion 106 of the forked member 82 in an alternating fashion to cause the forked member 82 to reciprocate. The forked member 82 reciprocates about the axis B and, in turn, transfers oscillating motion to the hollow spindle 98. When a center 92 of the shaft tip 94 is relatively far from the axis A (e.g., for relatively large eccentric distances), the ball bearing eccentric member 78 wobbles more than it does when the shaft tip 94 is relatively close to the axis A. A greater amount of wobble of the ball bearing eccentric member 78 corresponds to a greater degree of oscillation of the hollow spindle 98 about the axis B. Accordingly, an operator may change the degree of oscillation of the power tool 10 by changing the operating direction of the motor 22 or, alternatively, by engaging the reversing drive (not shown) to convert the rotation of the motor drive shaft 46 into rotation of the intermediate shaft (not shown) in an opposite direction of the motor drive shaft 46.
The oscillating tool 10 includes a switch 218 (
In operation, an operator actuates the switch 218 to select a larger degree of oscillation or a smaller degree of oscillation. The user then depresses the switch trigger 54 to engage the motor 22. If the operator has chosen the larger degree of oscillation, the motor 22 is actuated in the direction corresponding to the larger eccentric distance. If the operator has chosen the smaller degree of oscillation, the motor 22 is actuated in the direction corresponding to the smaller eccentric distance.
For example, in the illustrated construction, if the operator selects the larger degree of oscillation, the motor 22 operates in the first direction 194. The main shaft 66 rotates about the axis A in the first direction 194. Rotation of the main shaft 66 in the first direction 194 causes the first driving surface 142 of the eccentric bore 86 of the main shaft 66 to engage the first driven surface 182 of the eccentric member 70. Once the first driving surface 142 of the main shaft 66 is engaged with the first driven surface 182 of the eccentric member 70, the center 212 of the tip 94 of the eccentric member 70 is spaced the first eccentric distance 202 from the axis A. The ball bearing eccentric member 78 engaged with the tip 94 of the eccentric member 70 will push the arms 102 of the forked member 82 a first amount corresponding to the first eccentric distance 202, causing the clamping shaft 62 shaft to oscillate with the first degree of oscillation.
If the operator selects the smaller degree of oscillation, the motor operates in the second direction 206. The main shaft 66 rotates about the axis A in the second direction 206. By inertia, rotation of the main shaft 66 in the second direction 206 causes the second driving surface 146 of the eccentric bore 86 of the main shaft 66 to engage the second driven surface 186 of the eccentric member 70. Once the second driving surface 146 of the main shaft 66 is engaged with the second driven surface 186 of the eccentric member 70, the center 212 of the tip 94 of the eccentric member 70 is spaced the second eccentric distance 214 from the axis A. The ball bearing eccentric member 78 engaged with the tip 94 of the eccentric member 70 will push the arm of the forked member 82 a second amount corresponding to the second eccentric distance 214, causing the clamping shaft 62 to oscillate with the second degree of oscillation. Thus, the drive mechanism 58 includes an eccentric portion (e.g., the eccentric member 70) having a first amount of eccentricity with respect to the axis A when the main shaft 66 is driven in the first rotational direction and a second amount of eccentricity with respect to the axis A when the main shaft 66 is driven in the second rotational direction.
Thus, the invention provides an eccentric member 70 having a variable eccentricity to effectuate a change in the degree of oscillation of the output shaft (e.g., the hollow spindle 98) of the power tool 10. Changing the direction of rotation of the eccentric member 70 moves the eccentric member 70 to a different position having a different eccentricity. Thus, the invention provides a drive mechanism 58 operatively coupled to drive the output mechanism 60 at a first degree of oscillation when the main shaft 66 is driven in the first rotational direction and operatively coupled to drive the output mechanism 60 at a second degree of oscillation different from the first degree of oscillation when the main shaft 66 is driven in the second rotational direction. Various features and advantages of the disclosure are set forth in the following claims.
Filing Document | Filing Date | Country | Kind |
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PCT/CN2017/070751 | 1/10/2017 | WO | 00 |